Biodegradation efficacy of selected marine microalgae against Low-Density Polyethylene (LDPE): An environment friendly green approach

The present study dealt with the five marine microalgae strains viz., Chloroidium saccharophilum, Picochlorum maculatum, Amphora sp., Hymenomonas globosa and Limnospira indica and their effective degradation ability of Low-Density Polyethylene for the period of 45 days. The incubation of LDPE in microalgae culture has resulted in the maximum weight loss (20.16 ± 0.14 %), higher reduction rate (0.005/day) and lower half-life (138.4 days) in the LDPE treated with P. maculatum. The SEM images of all treated LDPE revealed surface erosion and the ATR-FTIR spectra showed functional group peaks along with new peaks at 1369.35 cm−1, 2332.96 cm−1 and 500–726 cm−1. Carbonyl (Keto, Ester), Vinyl and Internal double bond indices increased significantly in all the treated groups. The crystallinity was decreased (64.13 %) in P. maculatum treated LDPE than the control (71.37 %). Thermogravimetric analysis showed the reduction in thermal stability after biodegradation. This efficient microalgal degradation as a bioremediation technique will reduce the plastic pollution. [Display omitted] •LDPE can be biodegraded by a variety of marine microalgae including green algae, diatoms, cyanobacteria, and coccolithophore.•The green algae Picochlorum maculatum results maximum polymer weight loss of 20% within 45 days.•The physical and chemical modification of LDPE were examined by SEM and ATR-FTIR spectroscopy techniques.•Carbonyl index and Internal double bond index of biodegraded LDPE were found to be higher than the virgin LDPE.•The enzymatic response of the microalgae might have lowered the crystallinity and thermal stability of the polymer.